An update to the game in November 2017, titled “Plains of Eidolon”, added an open-world area to the game. The Plains are a semi-open world, initially accessible through a “hub” named Cetus, a settlement on Earth where a people named the Ostrons reside, then directly through the player’s ship. As the game describes them, the Ostrons are “A tight-knit band of hucksters and merchants.” This expansion added Warframe‘s first open-world experience to the game, the ability for the player to gain reputation with the Ostrons, side-activities of fishing and mining, a Bounty system, consisting of five missions of ascending difficulty, where the player can choose to play any mission they would like regardless of whether the previous ones have been completed, a new quest named Saya’s Vigil which rewarded the blueprint for the Warframe Gara, more customization options for the Tenno’s combat pets, Kubrows (dogs) and Kavats (cats/ocelots), and the ability for the Tenno themselves to wield their own modular weapon, called an Amplifier (or Amp, for short) as well as another modular blade called a “Zaw”. Finally, the “Plains of Eidolon” offer a new series of boss fights to the game: the titular Eidolons. These Sentient-origin titans require extreme gear and in most cases teamwork to take down for unique rewards.